SYDNEY, AUSTRALIA - JANUARY 13: Beachgoers enjoy the hot weather at Coogee Beach on January 13, 2016 in Sydney, Australia. Temperatures are expected to rise above 40 degrees in some parts of New South Wales today, with temperatures expected to be even higher on Thursday. (Photo by Zak Kaczmarek/Getty Images)

There's going to be a heatwave in Sydney. Eeek! It's going to be really, really hot. Yada yada yada.

But is it really?

There are widespread reports this Tuesday that there's going to be a midweek Sydney heatwave as we enter the last week of summer. There's just one small problem with those reports.

Let's start at the beginning. Has Bureau of Meteorology Forecast a Heatwave?

Yes it has. But it's in a fairly small area which encompasses the ACT and parts of southern NSW.

So what sort of temperatures are we talking about?

Sydney is tipped to reach 32 on Wednesday and 34 on Thursday.

Penrith, in Sydney's west, is one of the few areas with genuinely hot temperatures. It's tipped to reach 39 on Wednesday and 41 on Thursday. So parts of the Sydney area will be scorching but the city itself will be barely noticeably above average.

How does the Bureau actually define a heatwave?

It defines a heatwave thus: "Three days or more of high maximum and minimum temperatures that is unusual for that location."

But temperatures of 32 and 34 aren't particularly unusual

No they're not. Sydney's February average maximum is 26 degrees. Long term averages show that there will be 2.3 days of 30 degrees or more in any given February. Sydney has only had one such day so far this month, so it's probably due another one or two.

And anyway, shouldn't a heatwave be REALLY hot, not just a bit above average?

That's the thing. As mentioned above, the Bureau of Meteorology's definition of a heatwave is "high temperatures that are unusual for that location". There's nothing particularly unusual about this week's forecast. It's above average but nothing extreme.

In summary?

Chill out everybody. Which shouldn't be that hard because it's not actually THAT hot.